An anchor generally comprises several elements including ground engaging means usually in the form of one or more planar or curvilinear surfaces usually termed the fluke or flukes. Various fluke shapes are shown in U.S. Pat. Nos. to Danforth, 2,249,546 and 2,674,968, to Ogg 2,711,150, 2,840,029 and 3,024,756, to Bruce 3,777,695 and 4,134,356, to Towne 3,015,299 and 3,783,815, to Van den Haak 3,902,446, 3,964,421 and 4,089,288, to Taylor 1,974,933 and to Klaren 4,024,090. The fluke or flukes can be solid as in the aforementioned patents or hollow as in the Lenox U.S. Pat. No. 709,914, the Danforth U.S. Pat. No. 2,249,546 and in the POOL anchor of N. V. Koninklijke Nederlandsche Grofsmerderij.
In association with the aforementioned fluke surfaces, means are provided to facilitate and maintain the proper engagement of the aforesaid fluke surfaces with the bottom. Such means are usually termed the crown, the latter serving initially to lift the after end of the anchor to force the aforementioned fluke surfaces into bottom engagement.
Extending forwardly from the crown and in advance of such surfaces for attachment to an engaged cable or chain is a so-called shank. Shanks used heretofore have usually been in the form of a heavy, solid rectilinear bar. Various authors have pointed out that, particularly in a harder soil such as sand, penetration of an anchor into bottom is limited by the shank which slides over the bottom resisting penetration.
It has long been recognized that deep penetration into bottom is a prime factor in determining the efficiency of an anchor. If the anchor does not penetrate bottom, then the anchor structure merely slides across the bottom and the attempted anchoring is merely an exercise in futility.
To provide stability, one or more elements extending laterally from the fluke or flukes are provided to stabilize the entire anchor structure so that it does not rotate when subject to the pulling action applied to the shank by an attached rode. Such an element is frequently referred to as the stock.
The term "rode" is a nautical word of art commonly used to refer to the means (such as a rope, wire, chain, cable or the like) extended between a water supported object (such as a boat, ship, barge, drydock or the like) and a bottom engaging means such as an anchor, clump (U.S. Pat. No. 709,914) or the like.